Roaming of subscribers in areas covered by different network providers or operators is an already established and well-known principle. The subscribers which can be 2G (GSM=Global System for Mobile Communications) subscribers, 3G (UMTS=Universal Mobile Telecommunications System) subscribers or 4G (LTE=Long Term Evolution) subscriber are subscribers of a particular Public Land Mobile Network (PLMN) which can be named as their Home PLMN (H-PLMN). When a subscriber of an H-PLMN roams abroad the subscriber attaches to a PLMN in a visited network, named as Visited PLMN (V-PLMN) which identifies the foreign PLMN that the subscriber may attach to. Whilst the subscriber is attached to a particular V-PLMN the subscriber is served by the operator of the V-PLMN. Some call cases may be handled entirely in the V-PLMN whilst other services are partly executed in the H-PLMN and partly in the V-PLMN. An example for a call which is handled entirely in a V-PLMN is the establishment of a mobile originating (MO) call if no Customized Applications for Mobile network Enhanced Logic (CAMEL) control applies to the call. An example for a call partly handled in H-PLMN and V-PLMN is a mobile terminating (MT) call establishment. The concept of roaming abroad and attaching to a V-PLMN applies to circuit switched (CS) access, to packet switched (PS) access and to the evolved packet system (EPS) access.
To inform the user of a user equipment (UE) or mobile phone about the serving operator the name of the serving operator is shown on the display. The term “user equipment” is used but it may also be any other kind of mobile terminal or mobile phone, like a smartphone, a laptop or any other mobile equipment. When the UE is used in the H-PLMN the name of the H-PLMN is shown on the display. When the UE roams abroad it shows the name of a network to which the UE is attached at the display.
In one example the network name of the serving network is not broadcast by the network but a PLMN-identifier (PLMN-Id) is broadcast by a node of the serving network. This node can be a Base Transceiver Station (BTS), a NodeB or an enhanced NodeB (eNodeB) of the access network. The PLMN-id consists of a Mobile Country Code (MCC) and a Mobile Network Code (MNC) as standardized in 3GPP standard TS23.003 Version 11.5.0. The mobile terminal comprises a mapping table containing a relation between the PLMN-Id and the network name which is used globally. This mapping table in the mobile terminal is configured at production of the mobile terminal. Further it is possible to adapt the mapping table by adding new relations between a PLMN-Id and the network name.
Another possibility for providing the network name to the mobile terminal is standardized in the Network Identity and TimeZone (NITZ) standard 3GPP TS 22.042 Version 11.0.0. According to this standardized method the network name and time is provided to the mobile terminal by the PLMN and the mobile terminal shall present this information at the earliest opportunity to the user. 3GPP standard TS 24.008 Version 12.2.0 further specifies the corresponding signaling between the network and mobile terminal. The advantage of this method is that the provided network name can easy be adapted by the operator to override outdated PLMN-Id relations which are implemented during the production of the mobile terminal.
To implement new business models which may result in lower costs for the subscriber the European Commission (EC) mandates European operators to support a new concept known as Alternative Roaming Provider (ARP) as from Jul. 1, 2014. ARP entails that when a subscriber roams abroad the subscriber should have the possibility to obtain communication services from another operator than the H-PLMN operator who might have a roaming agreement with the V-PLMN operator. Therefore it is possible that the subscriber can select better conditions (price or service) when roaming to a location outside the H-PLMN coverage. The ARP acts as a Mobile Virtual Network Operator (MVNO) towards the subscriber. The subscriber's H-PLMN operator can be named as the Domestic Service Provider (DSP) in this context. The subscriber of the H-PLMN therefore has to sign a second subscription, namely a subscription with an ARP. When this subscriber roams with its UE within Europe (that is to say, countries within the European Community) the communication services are provided by the ARP instead of by the H-PLMN provider. The subscription to an ARP is optional and can be canceled. There also may be multiple ARPs which have different agreements with the operators. The usage of an ARP by an inbound roaming subscriber is transparent for the respective V-PLMN. The attachment of the inbound roaming subscriber to the V-PLMN is performed as normal. The V-PLMN does not differentiate between a regular inbound roaming subscriber attaching to this network and an inbound roaming subscriber who has signed up with an ARP, attaching to its network.
Further the EC stipulates that, besides ARP, also the possibility of a Local BreakOut (LBO) shall be offered to outbound roaming subscribers. LBO, as specified by the EU, entails that subscribers roaming within the EU should be able to acquire mobile data access in the foreign country through mobile data service offered by a Mobile Network Operator (MNO) in the visited country which can also be seen as an ARP. In LBO the data connection is established locally, i.e. through a Gateway GPRS Support Node (GGSN) in the V-PLMN. The data connection is charged by mobile data provider in the V-PLMN.
To inform the user about the current use of an ARP or a MNO/ARP in an LBO scenario there are some methods known in the prior art. The subscriber could receive a Short Message Service (SMS) message when roaming. The SMS comprises information about a possible ARP or an MNO. Further it is possible that the SMS comprises prices and other conditions. If the subscriber reverts to the H-PLMN services (e.g. because a prepaid credit is depleted) or the subscriber switches to another visited network operator for which ARP does not apply, the subscriber would then have to receive again an SMS message to inform about the changed conditions. Another possibility is to inform the user of a mobile terminal via an Unstructured Supplementary Service Data (USSD) message which provides a short-lived display notification. The USSD message appears on the screen for limited duration and is not stored in the phone. Both methods have the problem that the indication can easily be overlooked. In addition the display of information is only during a short time when USSD is used.
Another possibility is to install an application on a smartphone which checks the status and informs the user accordingly. This solution has the disadvantage that it requires data connection. This data connection is often switched off by the user (“data roaming—off”) to save costs.